6 to 9 million tonnes.
Mengjiangyuan, Li County, is located northeast of Xinzhou, Jin City, with an annual mining volume of 6-9 million tons. It is currently the largest sand and gravel mining area in Lishui.
Sand mining is the extraction of sand from rivers, which is used in the construction of high-rise buildings. It is an essential material in construction. It is mainly mixed with cement and other materials and used as concrete for construction.